Abstract-Band - Fakultät für Informatik, TU Wien - Technische ...

determined by the visible horizon, which can be approximated efficiently using a
multiresolution sampling approach. Local light sources are represented by
spherical lights and the incident radiance at receiver points is projected into the
spherical harmonic basis. Hence, this method produces convincing shadows on
dynamic height fields more efficiently than global illumination methods for
general geometry.
Johannes Novotny
Application of Smart Visibility on Medical 3D Ultrasound Datasets
Studium: Masterstudium Visual Computing
BetreuerIn: Ao.Univ.Prof. Dr. Eduard Gröller
Ultrasonography is one of the standard medical imaging techniques used in
pregnancy examinations. It is widely available due to its low cost, portability and
simple diagnostic procedure. Three-dimensional ultrasound (US) imaging has been
gaining popularity in the area of prenatal care recently. It provides examiners with a
coherent visualization of the fetus. However, within scanned 3D data sets, the fetus
is often surrounded by occluding structures which reduce its visibility in the
resulting visualizations. Current ultrasound machines provide several methods to
remove these occluders from visualizations. These methods are in general difficult
to control. As a result, the work flow of US examinations has to be interrupted in
order to apply occlusion removal to selected scans. To reduce the required user
interaction, this thesis evaluates a recently developed occlusion removal technique.
The smart visibility method for prenatal ultrasound uses a heuristic approach to
identify anatomic features within a data set. From these features, a clipping surface
that separates the fetus from its occluders is calculated. The use of the clipping
surface in combination with cutaway and ghosting visualization techniques allows
an unoccluded view of the fetus. The clipping surface calculated by the smart
visibility method is obtained by using a surface reconstruction algorithm. Within this
thesis, different surface reconstruction techniques were evaluated for their
occlusion removal quality and performance. It was possible to show that one of the
evaluated approaches provides good results in a majority of test cases. This
approach also reduces the required user interaction to a single parameter. By using
the hardware controls of an US machine to manipulate the adjustable parameter,
the smart visibility method can be used in realtime scenarios. GE Healthcare is
evaluating the smart visibility method and considers to include it in upcoming
versions of their US machine firmwares.
Simon Parzer
Irrational Image Generator
Studium: Masterstudium Medieninformatik
BetreuerIn: Ao.Univ.Prof. Dr. Eduard Gröller
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Mit Hilfe eines von Hofstetter Kurt entwickeltem Verfahren, genannt Inductive
Rotation (IR), kann auf einer zweidimensionalen Ebene aus einem einzigen